Published:January 01, 1972
Even the earliest ships to visit North America were equipped with lead lines for sounding shoals and coming to anchor as indicated by de Champlain’s detailed sounding charts of the harbors at Plymouth, Gloucester, and Chatham made in 1605 and 1607 (Howe, 1943, p. 112, 126, 136). After the region was settled, the growing fishing and shipping industry’s need for published charts led the United States Congress to establish the Survey of the Coast under the direction of F. R. Hassler (Wraight and Roberts, 1957). In 1835 the survey published its first sounding chart—one for the New York area. By 1843, about 30,000 sq km of the inner part of the continental shelf had been sounded. A. D. Bache succeeded Hassler and greatly expanded the operations of the bureau, which in 1878 was renamed the Coast and Geodetic Survey (now part of the Environmental Science Services Administration). A parallel bureau within the Navy Department was organized in 1830 to compile charts for deep water and foreign coasts (U.S. Navy Oceanographic Office, 1967). The first director of this Depot of Charts and Instruments was Lt. Charles Wilkes. In 1842, Lt. M. F. Maury succeeded Wilkes and expanded functions so that, in 1866, the depot became the Navy Hydrographic Office (now the U.S. Naval Oceanographic Office).
By the 1870s the major physiographic features of the shallow part of the continental margin were known. The edge of the shelf was found to be about 200 m deep and far from the shoreline.
Figures & Tables
Western North Atlantic Ocean: Topography, Rocks, Structure, Water, Life, and Sediments
The Atlantic coast of North America was the first part of the New World to be described by maps and texts; its exploration begain with the Vikings nearly a thousand years ago. Since then, the pace of exploration of both land and ocean floor has increased steadily. The concern during the 1960s was with details of geology, water, and life that largely were bypassed during earlier stages of discovery and exploration. The accumulation of knowledge was expressed approximately by the publication of charts, articles, and tabulations of data. This publication is concerned with the Atlantic continental margin of the United States, and it necessarily includes some information about the adjacent land and ocean areas. It is a summary of the existing knowledge of the ocean floor, the water above it, and the life that is in the water or at the bottom. The chapters contained within the publication fall into seven categories: Physiography, Rocks, Structure, Water, Life, Sediments, and Origin of Continental Margin.